Most electronic or computerized devices have electronic circuits that include one or more integrated circuits, often called “chips”. These integrated circuits are usually relatively large or complex circuits such as computer processors, memory arrays, or other such devices. The actual circuits in the integrated circuit are typically formed using semiconductor devices formed on a substrate, such as doped silicon transistors, resistors, and capacitors formed on a silicon substrate.
The combination of a substrate and circuitry formed on the substrate is often referred to as a “die”, and usually has circuitry that is so small that it is impossible to see the individual electronic components or circuit traces with the naked eye. Due to the small size of the circuit elements formed on the substrate, the die is also relatively fragile and can be easily damaged by scratching. Some circuits that operate at high power, such as high performance processors or controllers, also produce more heat than the integrated circuit die can dissipate, and so are not usable without some means of dissipating generated heat.
For these and other reasons, almost all integrated circuit dice are provided to the manufacturers of devices such as computers or cell phones in packages that are designed to protect the integrated circuit while making it easy to connect to other circuitry. Integrated circuit packages typically include pins, solder balls, or other electrical conductors that are coupled via small lead wires to various parts of the die's electrical circuits, enabling easy and reliable electrical connection from the package's exterior to the die's circuitry. These packages provide a variety functions not related to electrical connection, including carrying heat away from the die to the exterior of the circuit package and perhaps to an external heat sink, and protecting the relatively fragile die from environmental factors such as abrasion, moisture, and shock.
But, packaging an integrated circuit die has several challenges itself. Although a typical integrated circuit die is too small to form connections to without specialized equipment, it is still desirable to keep the size of the packaged die small so that it can be easily integrated into compact or portable electronic devices. The cost of the package is a significant concern, as complex packages that provide good heat management, good protection of the die, and easy connectivity to external circuitry can be a significant part of the cost of a packaged integrated circuit.
It is therefore desired to package integrated circuit dice in a manner that addresses such commercial needs.